500 internal error server

why is it that whenn i try to run unity i get a error that says 500 internal error server
what does this mean? how do i fix it please!!

The HTTP response 500 is returned by a webserver when there is an internal server error on the server itself. If you get that error in an empty project when you open Unity there might be a problem in Unity’s licensing server at the moment. However, i don’t get that error when i open any of my projects. I tried Unity 4.5 / 4.6 and the latest 4.6.1f1 (which i just installed).

It’s more likely that this error comes from your project itself. Either you try to connect to an external server that has an error, or you use some third party plugin that talks to their home server like the prime31 plugins for example. So if you have an error like this when you open Unity it’s probably some editor plugin code that tries to contact the developers server but that server has an error.

So it’s not really a problem in Unity. Try to pin down the problem. Does it also come up when you start Unity with a new, empty project? If not try to import one by one all those things you use in your actual project to see when it starts showing that error.